const watermark = {}
let watermarkId = ''
watermark.set = (options = {}) => {
  //默认设置
  let defaultSettings = {
    watermark_txt: 'text',
    watermark_x: 20, //水印起始位置x轴坐标
    watermark_y: 20, //水印起始位置Y轴坐标
    watermark_rows: 20, //水印行数
    watermark_cols: 20, //水印列数
    watermark_x_space: 50, //水印x轴间隔
    watermark_y_space: 50, //水印y轴间隔
    watermark_color: '#aaa', //水印字体颜色
    watermark_alpha: 0.3, //水印透明度
    watermark_fontsize: '16px', //水印字体大小
    watermark_font: '微软雅黑', //水印字体
    watermark_width: 120, //水印宽度
    watermark_height: 60, //水印长度
    watermark_angle: 15, //水印倾斜度数
    id: 'printBody', // 加水印元素
    ...options
  }

  watermarkId = defaultSettings.id

  //采用配置项替换默认值，作用类似jquery.extend
  if (arguments.length === 1 && typeof arguments[0] === 'object') {
    const src = arguments[0] || {}
    for (let key in src) {
      if (src[key] && defaultSettings[key] && src[key] === defaultSettings[key]) {
        console.log()
      } else if (src[key]) {
        defaultSettings[key] = src[key]
      }
    }
  }

  let oTemp = document.createDocumentFragment()

  //获取页面最大宽度
  let page_width = Math.max(
    document.body.scrollWidth,
    document.body.clientWidth
  )
  let cutWidth = page_width * 0.015
  page_width = page_width - cutWidth
  //获取页面最大高度
  let page_height =
    Math.max(document.body.scrollHeight, document.body.clientHeight) + 450
  // var page_height = document.body.scrollHeight+document.body.scrollTop;
  //如果将水印列数设置为0，或水印列数设置过大，超过页面最大宽度，则重新计算水印列数和水印x轴间隔
  if (
    defaultSettings.watermark_cols == 0 ||
    parseInt(
      defaultSettings.watermark_x +
      defaultSettings.watermark_width * defaultSettings.watermark_cols +
      defaultSettings.watermark_x_space *
      (defaultSettings.watermark_cols - 1)
    ) > page_width
  ) {
    defaultSettings.watermark_cols = parseInt(
      (page_width -
        defaultSettings.watermark_x +
        defaultSettings.watermark_x_space) /
      (defaultSettings.watermark_width +
        defaultSettings.watermark_x_space)
    )
    defaultSettings.watermark_x_space = parseInt(
      (page_width -
        defaultSettings.watermark_x -
        defaultSettings.watermark_width * defaultSettings.watermark_cols) /
      (defaultSettings.watermark_cols - 1)
    )
  }
  //如果将水印行数设置为0，或水印行数设置过大，超过页面最大长度，则重新计算水印行数和水印y轴间隔
  if (
    defaultSettings.watermark_rows == 0 ||
    parseInt(
      defaultSettings.watermark_y +
      defaultSettings.watermark_height * defaultSettings.watermark_rows +
      defaultSettings.watermark_y_space *
      (defaultSettings.watermark_rows - 1)
    ) > page_height
  ) {
    defaultSettings.watermark_rows = parseInt(
      (defaultSettings.watermark_y_space +
        page_height -
        defaultSettings.watermark_y) /
      (defaultSettings.watermark_height +
        defaultSettings.watermark_y_space)
    )
    defaultSettings.watermark_y_space = parseInt(
      (page_height -
        defaultSettings.watermark_y -
        defaultSettings.watermark_height * defaultSettings.watermark_rows) /
      (defaultSettings.watermark_rows - 1)
    )
  }
  let x
  let y
  for (let i = 0; i < defaultSettings.watermark_rows; i++) {
    y =
      defaultSettings.watermark_y +
      (defaultSettings.watermark_y_space +
        defaultSettings.watermark_height) *
      i
    for (let j = 0; j < defaultSettings.watermark_cols; j++) {
      x =
        defaultSettings.watermark_x +
        (defaultSettings.watermark_width +
          defaultSettings.watermark_x_space) *
        j

      let mask_div = document.createElement('div')
      mask_div.id = 'mask_div' + i + j
      mask_div.className = 'mask_div'
      mask_div.appendChild(
        document.createTextNode(defaultSettings.watermark_txt)
      )
      //设置水印div倾斜显示
      mask_div.style.webkitTransform =
        'rotate(-' + defaultSettings.watermark_angle + 'deg)'
      mask_div.style.MozTransform =
        'rotate(-' + defaultSettings.watermark_angle + 'deg)'
      mask_div.style.msTransform =
        'rotate(-' + defaultSettings.watermark_angle + 'deg)'
      mask_div.style.OTransform =
        'rotate(-' + defaultSettings.watermark_angle + 'deg)'
      mask_div.style.transform =
        'rotate(-' + defaultSettings.watermark_angle + 'deg)'
      mask_div.style.visibility = ''
      mask_div.style.position = 'absolute'
      mask_div.style.left = x + 'px'
      mask_div.style.top = y + 'px'
      mask_div.style.overflow = 'hidden'
      mask_div.style.zIndex = '9999'
      mask_div.style.pointerEvents = 'none' //pointer-events:none  让水印不遮挡页面的点击事件
      //mask_div.style.border="solid #eee 1px";
      mask_div.style.opacity = defaultSettings.watermark_alpha
      mask_div.style.fontSize = defaultSettings.watermark_fontsize
      mask_div.style.fontFamily = defaultSettings.watermark_font
      mask_div.style.color = defaultSettings.watermark_color
      mask_div.style.textAlign = 'center'
      mask_div.style.width = defaultSettings.watermark_width + 'px'
      mask_div.style.height = defaultSettings.watermark_height + 'px'
      mask_div.style.display = 'block'
      oTemp.appendChild(mask_div)
    }
  }
  document.getElementById(defaultSettings.id).appendChild(oTemp)
}

watermark.remove = () => {
  const wm = document.querySelectorAll('.mask_div')
  if (wm && wm.length > 0) {
    wm.forEach(ele => {
      document.getElementById(watermarkId).removeChild(ele)
    })
  }
}

export default watermark